/Engine/Plugins/FX/Niagara/Source/NiagaraEditor/Public/Widgets/SItemSelector.h
Whether or not to preserve the selection state when refresh is called. If true, OnGetKeyForItem must be set, and OnGetKeyForCategory and OnGetKeyForSection must be set if Categories or Sections are used, respectively.
WidgetArgsType & PreserveSelectionOnRefresh &40; bool InArg &41;